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Abstract

This article presents a wearable system that localizes people in the indoor environment, using data from inertial sensors. The sensors measure the parameters of human motion, tracking the movements of the torso and foot. For this purpose, they were integrated with shirt and the shoe insole. The values of acceleration measured by the sensors are sent via Bluetooth to a smartphone. The localization algorithm implemented on the smartphone, presented here, merges data from the shirt and the shoe to track the steps made by the user and filter out the localization errors caused by movements the shirt and torso. The experimental verification of the algorithm is also presented.

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Authors and Affiliations

Jaroslaw Kawecki
Pawel Oleksy
Lukasz Januszkiewicz
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Abstract

The removal of inclusions is a major challenge prior to the casting process, as they cause a discontinuity in the cast material, thereby lowering its mechanical properties and have a negative impact on the feeding capability and fluidity of the liquid alloys. In order to achieve adequate melt quality for casting, it is important to clean the melts from inclusions, for which there are numerous methods that can be used. In the course of the presented research, the inclusion removal efficiency of rotary degassing coupled with the addition of different fluxes was investigated. The effects of various cleaning fluxes on the inclusion content and the susceptibility to pore formation were compared by the investigation of K-mold samples and the evaluation of Density Index values at different stages of melt preparation. The chemical composition of the applied fluxes was characterized by X-ray powder diffraction, while the melting temperature of the fluxes was evaluated by derivatographic measurements. It was found that only the solute hydrogen content of the liquid metal could be significantly reduced during the melt treatments, however, better inclusion removal efficiency could be achieved with fluxes that have a low melting temperature.

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Authors and Affiliations

M. Máté
M. Tokár
G. Fegyverneki
G. Gyarmati
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Abstract

The paper presents FEM approach for comparative analyses of wall connections applied in cast grates used for charge transport in furnaces for heat and thermal-chemical treatment. Nine variants of wall connection were compared in term of temperature differences arising during cooling process and stresses caused by the differences. The presented comparative methodology consists of two steps. In first, the calculations of heat flow during cooling in oil for analysed constructions were carried out. As a result the temperature distributions vs cooling time in cross-sections of analysed wall connections were determined. In the second step, based on heat flow analyses, calculations of stresses caused by the temperature gradient in the wall connections were performed. The conducted calculations were used to evaluate an impact of thermal nodes reduction on maximum temperature differences and to quantitative comparison of various base design of the cast grate wall connection in term of level of thermal stresses and their distribution during cooling process. The obtained results clearly show which solution of wall connection should be applied in cast grate used for charge transport in real constructions and which of them should be avoided because the risk of high thermal stresses forming during cooling process.
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Bibliography

[1] Lai, G.Y. (2007). High-Temperature Corrosion and Materials Applications. ASM International.
[2] Davis, J.R. (Ed.). (1997). Industrial Applications of HeatResistant Materials. In Davis, J.R. (Eds.), ASM Specialty Handbook - Heat-Resistant Materials (pp. 67-85). ASM International.
[3] Piekarski, B. (2012). Creep-resistant castings used in heat treatment furnaces. Szczecin: West Pomeranian University of Technology Publishing House. (in Polish).
[4] Ul-Hamid et al. (2006). Failure analysis of furnace tubes exposed to excessive temperature. Engineering Failure Analysis. 13(6), 1005-1021. DOI: 10.1016/j.engfailanal.2005.04.003.
[5] Reihani, A., Razavi, S.A., Abbasi, E. et al. (2013). Failure Analysis of welded radiant tubes made of cast heat-resisting steel. Journal of failure Analysis and Prevention. 13, 658–665. DOI: https://doi.org/10.1007/s11668-013-9741-y.
[6] Piekarski, B. (2010). Damage of heat-resistant castings in a carburizing furnace. Engineering Failure Analysis. 17(1), 143-149. DOI: 10.1016/j.engfailanal.2009.04.011.
[7] Nandwana, D., et al. (2010). Design, Finite Element analysis and optimization of HRC trays used in heat treatment process. In World Congress on Engineering 2010, June 30 - July 2, 2010 (pp. 1149-1154). London, U.K.: Newswood Limited.
[8] Sandeep, K., Ajit, K. & Mahesh, N.S. (2012). Improving productivity in a heat treatment shop for piston Pins. SASTECH Journal. 11(2), 38-46.
[9] Standard PN-EN 10295: 2004. Heat resistant steel castings.
[10] Bajwoluk, A. & Gutowski, P. (2019). Thermal stresses in the accessories of heat treatment furnaces vs cooling kinetics. Archives of Foundry Engineering. 19(3), 88-93, DOI: 10.24425/afe.2019.127146.
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Authors and Affiliations

A. Bajwoluk
1
ORCID: ORCID
P. Gutowski
1
ORCID: ORCID

  1. Mechanical Engineering Faculty, West Pomeranian University of Technology, Szczecin, Al. Piastów 19, 70-310 Szczecin, Polska
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Abstract

The study reported in this paper was aimed at establishing the effect of values of parameters characterizing the process of superficial remelting of a nodular iron casting on the quantity of introduced heat, geometry of remeltings as well as parameter λ and hardness of cementite eutectic. The remelting process was carried out using GTAW method, at electric arc length of 3 mm in argon atmosphere, welding current intensities I = 50, 130, 210, and 300 A, and electric arc scanning speeds vs = 200, 400, and 800 mm/min. The measurements included estimation of the quantity of heat introduced to the casting in the electric arc-induced remelting process with the use of flow calorimeter. Widths and depths of remetlings were assessed with the use of metallographic method. As a result of fast solidification, cementite eutectic was obtained in remelted material in which, in the course of cooling down to ambient temperature, austenite was subject to partial transformation into martensite. To characterize the cementite eutectic, value of the structural parameter λ was assessed. Values of the parameter were similar for areas of occurrence of both fibrous and laminated eutectic. Remeltings were examined at half of their depths. Micro-hardness measurements were taken in the same areas. The established quantitative relationships may prove to be useful in practice for the purpose of predicting values of parameter λ and hardness of remeltings in studies aimed at improving resistance of cast-iron castings to abrasive wear.
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Authors and Affiliations

M. Korzeniowski
A. Trytek
B. Kupiec
A.W. Orłowicz

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